Background. Retinoblastoma shows high rates of recurrence after initial chemotherapy (systemic or intraarterial). Our aim was to evaluate the effectiveness of iodine-125 radioactive plaque brachytherapy as a salvage treatment with globe-preserving attributes after initial chemotherapy in patients with intraocular retinoblastoma.

Methods. The effect of brachytherapy was investigated retrospectively in 17 eyes of 17 patients who were followed up due to retinoblastoma between May 2012 and June 2018 and who received iodine-125 radioactive plaque brachytherapy as a salvage treatment after systemic or intra-arterial chemotherapy. The regression, ocular toxicity, and enucleation rates were evaluated at the end of the follow-up period.

Results. The tumor locations were post equator, macular, anterior to the equator, and peripapillary in 5, 3, 7, and 2 patients, respectively. Regression was initially and rapidly observed in 17 of the 17 eyes that underwent brachytherapy. Enucleation was performed in 5 (29.42%) of these patients due to recurrence with diffuse tumor involvement, and 4 of the tumors were located anterior to the equator. In 12 (70.58%) patients, the eyes were protected from enucleation following local brachytherapy.

Conclusions. Radioactive plaque brachytherapy can be applied as an effective salvage therapy with successful results in retinoblastoma patients who have received initial systemic or intra-arterial chemotherapy. Post equator-located solitary tumors have the highest success rate.

Keywords: brachytherapy, cancer, eye, iodine-125, retinoblastoma